Experimental Simulation of Oxygen Consumption by Bottom Sediment in the Liao River Estuary

The low dissolved oxygen (DO) concentration in the Liao river estuaries is a very serious ecological problem. Problems can be caused by the release of oxygen consumption matter originating from the bottom sediment, which has a high concentration of organic matter. The major reason for DO decline and water body fetor is the release of organic matter in the sediment and the mineralization of oxygen consumption. The impact of the estuarine water DO on the nutrients in sediments was investigated by experimental simulations. The changes in environmental factors such as the nutrients in the water that overlies the sediment in the Liao river was analyzed, and was associated with the DO concentration in order to discover the reason for the formation of low-oxygen water in the estuaries. The experimental simulation results indicated that the DO concentration in the sediment overlaying water was lower than in the main water body, and the COD in the sediment overlaying water was higher than in the main water body. The results prove that the sediment is a vital factor that affects the DO concentration in the sediment overlaying water. Correlative analysis indicates that nutrients showed better correlativity with the DO in the main water body than in the sediment overlaying water. Because the gross of the nutrients in the overlaying water varies greatly due to the nutrients released from the sediment, analysis of the correlativity is impossible. The organic matter in the overlaying water has a great effect on the DO content in the main water body.